The Nikon D5000 is the poor mans D90 (my husband just read that online last night). I just got one for my husband for Christmas. It is a WONDERFUL camera! A big difference between the D3000 and the D5000 is the 3000 is a 10.1MP and the 5000 is a 12.3MP the 5000 also has the tilt screen and take 4frame per second where the 3000 take 3frames per second.
I got a great deal for the D5000 on
www.ritzcamera.com it was $799 with free shipping, no tax and an extra lense.
I LOVE the Nikon cameras. It is a fact that they have the best lenses and that makes a large difference when taking photos.
Good luck.